Engine-cooling system

ABSTRACT

An engine-cooling system including dual low-configuration, sideby-side cooling fans whose pulleys may be operated by the same endless belt, or by two separate belts, from a single- or multigroove pulley, respectively, secured to a single thermostatically controlled viscous fluid, shear-type clutch for variable speed ratios with respect to engine speed, in response to varying ambient temperatures.

United States Patent [72] Inventor TheodoreN.Louckes Lanslng,Mic1I. 211 AppLNo. 823,591 [22] Filed May 12,1969 [4S] Patented Aug. 24, 1971 [73] Assignee General MotorsCorpor-atlon Detroit,M1e1r.

s41 ENGINE-COOLING svsrm 4Claims,8DnwlngFigs.

[52] U.S.C1. 123/41.12, 123/4146, 123/4151 [51] InLCI. F01p7/12 [50] FieldofSearch 123/41.l1, 41.12,41.47,195A,41.49,41.46,41.51,41.31

[56] ReferenoesCited UNITED STATES PATENTS 2,095,058 10/1937 Cross 123/4151 2,265,078 12/1941 Marsh 123/41.46

2,802,459 8/1957 Herbenar r 123/41.12

2,807,246 9/1957 Jacobs.. 123/41.12

3,493,272 3/1970 Roper 123/4131 FOREIGN PATENTS 871,220 3/1953 Germany l23/41.49

Primary Examiner-Mark M. Newman Assistant Examiner-Cort R. Flint Att0rneys Warren E. Finken, A. M. Heiter and John P.

Moran ABSTRACT: An engine-cooling system including dual lowconfiguration, side-by-side cooling fans whose pulleys may be operated by the same endless belt, or by two separate belts, from a singleor multigroove pulley, respectively, secured to a single thermostatically controlled viscous fluid, shear-type clutch for variable speed ratios with respect to engine speed, in response to varying ambient temperatures.

PATENTED AUG24 I97:

SHEET 1 [IF 4 PATENTEU AUB24I97| 3301.100

SHEET 2 UF 4 63 lNVliN'lYlR iheodoreN [ouches ATTORNEY PATENTEU AUG24 |97| SHEET .3 BF 4 B Y jheodore Q 1 #WW ATTORNEY PATENTEU AUG24 I97! SHEET 0F 4 ENGINE-COOLING SYSTEM This invention relates to automotive engine cooling systems and more particularly to a cooling system wherein dual cooling fans are driven from one thermostatically controlled, viscous fluid, shear-type clutch.

Due to current trends in automobile styling toward lower, wider front end configurations, the single fan of the conventional cooling system must at times be reduced in diameter and/or operated at a faster speed. The novel dual-fan design of the present invention provides the necessary lower configuration, and, when adapted for use with a viscous fluid clutch, results in more efficient airflow distribution and less fan noise. It has been determined that a smoother laminar flow results from the two-fan arrangement and that fan noise characteristics have been greatly improved, there being minimal discontinuity in airflow which otherwise causes noise. More specifically, the two fans can be more strategically located adjacent radiator areas which are not in line with baffles and tanks, etc., thereby subjecting the blades to a more constant torque than is the case with discontinuous airflow, which alternately relaxes and pulls on the individual blades, causing bothersome sound wave pulsations.

Accordingly, a primary object of the invention is to provide a dual-fan engine cooling system wherein two fans are driven from one thermostatically controlled viscous fluid, shear-type clutch.

Another object of the invention is to provide a dual-fan cooling system wherein the dual fans are located side by side in an overall lower configuration such that air is distributed over the entire engine area in a highly efficient manner and with reduced fan noise.

A further object of the invention is to provide a dual-fan cooling system, wherein the need for fan shrouds is eliminated, thereby reducing restrictions for good high-speed cooling and further reducing fan noise.

Other objects and-advantages of the invention will become apparent when reference is made to the following specification ad accompanying drawings wherein:

FIG. 1 is an end view of an automotive engine accessory drive system embodying the invention;

FIG. 2 is a top view taken along the plane of line 2-2 of FIG. 1, and looking in the direction of the arrows;

FIG. 3 is a perspective view of the accessory drive system embodying the invention;

FIG. 4 is an enlarged fragmentary cross-sectional view of a portion of FIG. 1, taken along the plane of line 4-4, and looking in the direction of the arrows;

FIG. 5 is a fragmentary top view of a modification of the FIGS. 1-3 structure;

FIG. 6 is an end view of a modified automotive engine accessory drive system embodying the invention;

FIG. 7 is a top view taken along the plane of line 77 of FIG. 6, and looking in the direction of the arrows; and

FIG. 8 is a perspective view of the modified accessory drive system embodying the invention,

Referring now to the drawings in greater detail, FIGS. l3 illustrate an automotive engine accessory drive system 10, wherein engine cooling is provided by two side-by-side fans 12 and 14 located directly behind the radiator 13, both fans being driven by a multigroove front portion 15 of a coupling pulley 16, as will be described. The front pulley portion 15 is rotatably mounted on bearings 17 on a shaft 18 extending from an engine 20. An endless belt 22 is mounted around a first groove 24 formed in the front portion 15 of the coupling pulley 16. a first groove 26 formed in an upper idler pulley 28 and a fan pulley 30. The fan 12 is secured to a flange 32 by any suitable means, such as bolts 34. The flange 32 is secured to a shaft 36 extending from the fan pulley 30, the latter being rotatably mounted on a fixed shaft 37 extending from the front of the engine 20.

A second endless belt 38 is mounted around a second groove 40 formed in the coupling pulley 16, a second groove 42 formed in the upper idler pulley 28 and a second fan pulley 44. The fan 14 is secured to a flange 46 by bolts 48, the flange 46 being secured to a shaft 50 extending fromthe fan pulley 44, which, in turn, is rotatably mounted on a fixed shaft 51 extending from the front of the engine 20. The shaft 50 is longer than the other fan shaft 36 by an amount sufiicient to cause the fan 14 to rotate in the same plane as the fan 12, the fan pulley 44 being located behind the fan pulley 30, as viewed in FIG. 2.

A thermostatically controlled viscous fluid, shear-type clutch 52 is also rotatably mounted on the bearings 17, the front portion 15 of the coupling pulley 16 being secured to a housing 54 of the clutch 52. The speed of the coupling pulley portion 15 is controlled by the viscous fluid clutch 52 such that the fans 12 and 14 will be running at a relatively high speed for maximum cooling at low engine speed and at a substantially lower speed when the engine 20 is running in direct drive at road speeds when the necessity for fan cooling is diminished. The resultant lower fan speed eliminates excessive fan noise which otherwise could be disturbing to the occupants of the vehicle.

Other accessory drive mechanisms are driven by a rear portion 56 of the coupling pulley 16, the rear portion 56 being secured to the shaft 18 for rotation therewith.

A third endless belt 58 is mounted around an air pump pulley 60, a first groove 62 (FIG. 3) formed in a lower idler pulley 64, and a first groove 66 formed in the rear portion 56 of the coupling pulley 16, directly in front of the engine 20.

A fourth endless belt 68 is mounted around a generator pulley 70, a power steering pump pulley 72, and second grooves 74 and 76 formed in the lower idler pulley 64 and in the rear portion 56 of the coupling pulley 16, respectively, the grooves 74 and 76 being locatedin the same plane as the generator and power steering pump pulleys 70 and 72. The latter plane is positioned directly in front of the plane of the groove 66, as viewed in FIG. 2.

A fifth endless belt 78 is mounted around an air conditioner compressor pulley 80, a third groove 82 (FIG. 3) formed in the lower idler pulley 64 and a third groove 84 formed in the rear portion 56 of the coupling pulley, immediately in front of the plane of the second rear coupling groove 76, as viewed in FIG. 2.

It should be noted that the rear portion 56 of the coupling pulley 16 rotates with the shaft 18, thus causing the generator, power steering pump, air-conditioning compressor, and air pump to be rotated at constant speed ratios with respect to engine speed, as determined by their respective pulley sizes.

Referring now to FIG. 4, it may be noted that a viscous fluid, shear-type clutch plate 55, within the housing 54 of the clutch assembly 52, is secured to the end of the shaft 18 for rotation therewith, while the housing 54 and its associated front coupling pulley portion 15 will rotate on the bearing assembly 17 at a variable speed ratio with respect to the speed of the shaft 18, depending upon the viscosity of the fluid 57 in the housing 54 and the location of same with respect to the conventional internal ridge and groove shear-type drive members 59 and 61, respectively, and a reservoir 63. The fluid 57 within the housing 54 is at times substantially entirely within the reservoir 63 and, at times, at the level indicated in FIG. 4. This will vary the speed ratio between the shaft 18 and the front pulley portion 15 in response to ambient temperature changes in the spaced between the radiator and the engine 20, as detected by a helical, bimetallic thermostatic spring 85 in the well-known manner of actuating a valve 65 for controlling flow ofthe fluid 57 through an opening 67.

As illustrated in FIG. 5, it may be desirable to actuate the power steering pump pulley 72 by means of the belt 38 which drives the fan pulley 44, and have the belt 68 drive the generator pulley 70 only, inasmuch as the lower speed prevailing at idle and during parking maneuvers is sufficient for the power steering pump.

Referring now to FIGS. 6-8, the embodiment illustrated therein includes a pair of fans 86 and 88 located in the space directly behind a radiator 89 and secured by bolts 90 to two identical flanges 92 on identical shafts 94 extending from fan pulleys 96 and 98, respectively, which, in turn, are rotatably mounted on the front of the engine 20.

A first endless belt 100 is mounted around the fan pulleys 96 and 98 and around a single-groove front portion 101 of a coupling pulley 102. The coupling pulley 102 is secured to a housing 104 of a thermostatically controlled viscous fluid, shear-type clutch 106. The clutch 106 is mounted on a bearing 108 which, in turn, is rotatably mounted on a shaft extending from the engine 20. The speed of the coupling pulley 102, and hence, of the fan pulleys 96 and 98, is controlled by the clutch 106 in the manner described above relative to the clutch 52. The clutch 106 is mounted behind the fans 86 and 88, as viewed in FIG, 7. A bimetallic spring 1 11 is mounted on the front of the clutch 106 and responds to ambient temperature changes to operate a valve arrangement within the clutch housing 104 for controlling the location of the fluid therein, and hence the relative speeds of the shaft 110 and the pulley 102, as discussed above relative to FIG. 4.

A second endless belt 112 is mounted around an air conditioner compressor pulley 114, a first groove 116 formed in an idler pulley 118 and a first groove 120 (FIG. 8) formed in a rear portion 122 of the coupling pulley 102, in a plane behind the plane of the fan pulleys 96 and 98, as viewed in FIG. 7.

It is apparent that the front and rear portions 101 and 122 of the coupling pulley 102 may rotate at different speeds, as was explained above relative to the front and rear portions and 56, respectively, ofthe coupling pulley 16.

A third endless belt 124 is mounted in a first groove 126 formed in a power steering pump pulley 128, a second groove 130 formed in the idler pulley 118 and a second groove 132 (FIG. 8) formed in the rear portion 122 of the coupling pulley 102, in a plane located directly behind the plane of the air conditioner compressor pulley 114, as viewed in FIG. 7.

A fourth endless belt 134 is mounted around a generator pulley 136, a second groove 138 formed in the power steering pump pulley 128, a third groove 140 (FIG. 8) formed in the rear portion 122 of the coupling pulley 102, and a third groove 142 formed in the idler pulley 118, in a plane located behind the plane of the power steering pump pulley 128 and in front of the engine 20, as viewed in H6. 7.

It may be realized that the power steering pump pulley 128 may be extended from the engine into the plane of the fan pulleys 96 and 98 and driven by the belt 100, rather than by the belt 134, for the reasons set forth above relative to FIG. 5.

It should be apparent from the above description that the dual fan arrangement results in a desirable lower and wider cooling system and, v den adapted for use with a single thermostatically controlled viscous fluid shear-type clutch, providt novel means for controlling airflow as required for the full engine operating range. The shape of the airflow characteristics curve may be controlled, providing, for example, excellent low-speed cooling possibilities, with resultant decreased fan noise, and without the need for the conventional shroud normally used to increase airflow at low speeds. Being able to eliminate fan shrouds reduces restrictions which heretofore were detrimental in obtaining food high-speed cooling characteristics.

It may be further realized that the broken lines outlining the radiators l3 and 89 in FIGS. 1 and 6, respectively, may represent that portion of a radiator which is not in line with the usual associated tanks and/or baffles. This will permit the blades to rotate under substantially constant torque, without having to move through intermittent or spaced airflow streams. As a result, by virtue of the blades not being subjected to alternate relaxing and pulling, sound wave pulsations will be diminished and the noise level reduced accordingly.

While but three embodiments of the invention have been shown and described, other modifications thereof are possible.

lclaim:

1. For use with an automotive engine having a rotating shaft extending therefrom, an engine-cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being rotatably mounted on said shaft, and a clutch plate member secured to the end of said shaft and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive therebetween; front coupling pulley means secured to said rear wall of said housing for rotation therewith; first and second fan pulleys rotatably mounted on opposite sides of said front coupling pulley means; first and second fans secured to said first and second fan pulleys, respectively; endless belt means operatively connected around said front coupling pulley means and each of said first and second fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with respect to the speed of said rotating shaft; rear coupling pulley means secured to said rotating shaft; at least one engine accessory pulley; an endless belt operatively connected around said engine accessory pulley and said rear coupling pulley means for rotating said engine accessory pulley at a constant speed ratio with respect to the speed of said rotating shaft, and a I power steering pump pulley mounted in the plane of at least one of said fan pulleys and said front coupling pulley means and adapted to be driven by said endless belt means operatively connected around said fan pulleys and said front coupling pulley means.

2. For use with an automotive engine having an engine drive shaft extending therefrom, an engine cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being axially fixed on said shaft, and a clutch plate member secured directed to the end of said shaft for drive thereby and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive from said plate to said housing; pulley groove means formed on said rear wall of said housing; first and second driven fan pulleys rotatably mounted on opposite sides of said pulley groove means on said rear wall; first and second fans secured to said first and second driven fan pulleys, respectively; endless belt means operatively connected around said pulley groove means and each of said first and second fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with a respect to the speed of said engine-rotated shaft; a multiple-groove idler pulley; a multiple-groove drive pulley directly secured to said engine-rotated drive shaft between the viscous fluid clutch and the engine and driven thereby; a plurality of engine accessory driven pulleys; and a plurality of endless belts with one belt connected around each of said plurality of engine accessory driven pulleys and some one groove of said multiple-groove drive pulley and some one groove of said multiple-groove idler pulley for rotating said engine accessory driven pulleys at a constant speed ratio with respect to the speed of said engine-rotated shaft.

3. For use with an automotive engine having an engine drive shaft extending therefrom, an engine-cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being axially fixed on said shaft, and a clutch plate member secured directly to the end of said shaft for drive thereby and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear spaced therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive from said plate to said housing; a pair of drive pulley grooves formed on said rear wall of said housing; an idler pulley having a pair of pulley grooves formed therein; first and second driven fan pulleys rotatably mounted on opposite sides of said pair of drive pulley grooves on said rear wall; first and second fans secured to said first and second driven fan pulleys, respectively; separate endless belt means respectively operatively connected around each of said idler pulley grooves, each of said pair of grooves on said rear wall, and each of said first and second fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with respect to the speed of said engine-driven shaft, a multiple-groove idler pulley; a multiple-groove drive pulley directly secured to said engine-rotated drive shaft between the viscous fluid clutch and the engine and driven thereby; a plurality of engine accessory driven pulleys; and a plurality of endless belts with one belt connected around each of said plurality of engine accessory driven pulleys and some one groove of said pulley grooves of said multiple-groove drive pulley and some one groove of said multiple-groove idler pulley for rotating said engine accessory driven pulleys at a constant speed ratio with respect to the speed of said engine-rotated shaft.

4. For use with an automotive engine having an engine drive shaft extending therefrom, an engine-cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being axially fixed on said shaft, and a clutch plate member secured directly to the end of said shaft for drive thereby and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive from said plate to said housing; a single-groove pulley formed on said rear wall of said housing; first and second driven fan pulleys rotatably mounted on opposite sides of said front single-groove pulley and at different levels therewith; first and second fans secured to said first and second driven fan pulleys, respectively; an endless belt mounted around said single-groove pulley and extending in opposite directions therefrom to and around each of said first and second driven fan pulleys and thence directly between said fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with respect to the speed of said enginerotated shaft; a multiple-groove idler pulley; a multiple-groove drive pulley directly secured to said engine-rotated drive shaft between the viscous fluid clutch and the engine and driven thereby; a plurality of engine accessory driven pulley; and a plurality of endless belts with one belt mounted around each of said engine accessory driven pulleys and some one groove of said multiple-groove drive pulley and some one groove of said multiple-groove idler pulley for rotating said engine accessory driven pulleys at a constant speed ratio with respect to the speed of said engine-rotated shaft. 

1. For use with an automotive engine having a rotating shaft extending therefrom, an engine-cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being rotatably mounted on said shaft, and a clutch plate member secured to the end of said shaft and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive therebetween; front coupling pulley means secured to said rear wall of said housing for rotation therewith; first and second fan pulleys rotatably mounted on opposite sides of said front coupling pulley means; first and second fans secured to said first and second fan pulleys, respectively; endless belt means operatively connected around said front coupling pulley means and each of said first and second fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with respect to the speed of said rotating shaft; rear coupling pulley means secured to said rotating shaft; at least one engine accessory pulley; an endless belt operatively connected around said engine accessory pulley and said rear coupling pulley means for rotating said engine accessory pulley at a constant speed ratio with respect to the speed of said rotating shaft, and a power steering pump pulley mounted in the plane of at least one of said fan pulleys and said front coupling pulley means and adapted to be driven by said endless belt means operatively connected around said fan pulleys and said front coupling pulley means.
 2. For use with an automotive engine having an engine drive shaft extending therefrom, an engine cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being axially fixed on said shaft, and a clutch plate member secured directed to the end of said shaft for drive thereby and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive from said plate to said housing; pulley groove means formed on said rear wall of said housing; first and second driven fan pulleys rotatably mounted on opposite sides of said pulley groove means on said reaR wall; first and second fans secured to said first and second driven fan pulleys, respectively; endless belt means operatively connected around said pulley groove means and each of said first and second fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with a respect to the speed of said engine-rotated shaft; a multiple-groove idler pulley; a multiple-groove drive pulley directly secured to said engine-rotated drive shaft between the viscous fluid clutch and the engine and driven thereby; a plurality of engine accessory driven pulleys; and a plurality of endless belts with one belt connected around each of said plurality of engine accessory driven pulleys and some one groove of said multiple-groove drive pulley and some one groove of said multiple-groove idler pulley for rotating said engine accessory driven pulleys at a constant speed ratio with respect to the speed of said engine-rotated shaft.
 3. For use with an automotive engine having an engine drive shaft extending therefrom, an engine-cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being axially fixed on said shaft, and a clutch plate member secured directly to the end of said shaft for drive thereby and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear spaced therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive from said plate to said housing; a pair of drive pulley grooves formed on said rear wall of said housing; an idler pulley having a pair of pulley grooves formed therein; first and second driven fan pulleys rotatably mounted on opposite sides of said pair of drive pulley grooves on said rear wall; first and second fans secured to said first and second driven fan pulleys, respectively; separate endless belt means respectively operatively connected around each of said idler pulley grooves, each of said pair of grooves on said rear wall, and each of said first and second fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with respect to the speed of said engine-driven shaft, a multiple-groove idler pulley; a multiple-groove drive pulley directly secured to said engine-rotated drive shaft between the viscous fluid clutch and the engine and driven thereby; a plurality of engine accessory driven pulleys; and a plurality of endless belts with one belt connected around each of said plurality of engine accessory driven pulleys and some one groove of said pulley grooves of said multiple-groove drive pulley and some one groove of said multiple-groove idler pulley for rotating said engine accessory driven pulleys at a constant speed ratio with respect to the speed of said engine-rotated shaft.
 4. For use with an automotive engine having an engine drive shaft extending therefrom, an engine-cooling system comprising a viscous fluid clutch including a housing mounted on a bearing, said bearing being axially fixed on said shaft, and a clutch plate member secured directly to the end of said shaft for drive thereby and rotatably mounted in said housing for variable relative rotation therewith, said clutch plate member and the rear wall of said housing having opposed, spaced parallel surfaces defining a fluid shear space therebetween and cooperable with a fluid medium in said shear space to provide a shear-type fluid drive from said plate to said housing; a single-groove pulley formed on said rear wall of said housing; first and second driven fan pulleys rotatably mounted on opposite sides of said front single-groove pulley and at different levels therewith; first and second fans secured to said first and second driven fan pulleys, respectively; an endless belt mounted around said single-groove pUlley and extending in opposite directions therefrom to and around each of said first and second driven fan pulleys and thence directly between said fan pulleys for rotating said fan pulleys at a constant speed ratio with respect to the speed of said housing and at a variable speed ratio with respect to the speed of said engine-rotated shaft; a multiple-groove idler pulley; a multiple-groove drive pulley directly secured to said engine-rotated drive shaft between the viscous fluid clutch and the engine and driven thereby; a plurality of engine accessory driven pulley; and a plurality of endless belts with one belt mounted around each of said engine accessory driven pulleys and some one groove of said multiple-groove drive pulley and some one groove of said multiple-groove idler pulley for rotating said engine accessory driven pulleys at a constant speed ratio with respect to the speed of said engine-rotated shaft. 